Apparatus for drying cut staple



May 18, 1954 w. A. KNOPP 2,678,504

APPARATUS FOR DRYING'CUT STAPLE Filed June 14, 1951 INVENTOR. )1 WALLACEA. KNOPP N BY - ATTORNIK LL v Patented May 18, 1954 UNITED STATES PATENTOFFICE APPARATUS FOR DRYING CUT STAPLE Wallace A. Knopp, Parkersburg, W.Va., assignor to American Viscose Corporation,.Wilmington,. DeL, a,corporation of Delaware Application June 14, 1951, Serial No. 231,607

7 Claims. 1

This invention relates toan' apparatus for drying out staple. Moreparticularly, the invention is concerned with drying out staplecontinuously in spread-out fashion and provides a method and means forperiodically redistributing the staple in the layer during the course ofdrying thereof.

It is generally the practice when drying staple fibers to form the sameinto a mat or blanket of varying thickness depending upon the type offiber, but usually on the order of one to three inches in thickness, andthen to pass such mat or blanket through a dryer comprising a chamber orhousing. Various problems and difllculties are encountered in such asystem. For example, it is diiiicult to form mats or blankets of staplefibers which are uniform in depth and density and this results inspottyover-drying and spotty under-drying in the blanket. In addition,the outside of the blanket dries faster than the interior thereof whichresults in nonuniform drying. Also, to insure thorough drying, theblanket of staple must be kept in the dryer a long length of time whichnaturally limits production. Thus, there is still much to be desired inthe use of a conveyor type dryer in drying out staple fibers.

It is an objectof the present invention to overcome the aforementioneddifficulties and disadvantages and provide an improved apparatus fordrying out staple fibers. Specifically it is an object of the presentinvention to provide a new apparatus of the conveyor dryer type which\villdry staple fibers more uniformly and at an increased rate of speed.Further, it is another specific object of the present invention toprovide a new apparatus for drying a blanket or mat of staple fiberscontinuously comprising means for redistributing the fibers in the mator blanket without the use of movable-mechanical parts which are subjectto wear. Other objects and advantages, of the. present invention will beapparent from the description thereof hereinafter. J

In general, the objects of thepresent invention are accomplished byforming, the staple fibers into a mat or'blanket in the usual manner,such as on a screen or roller, etc, and then passing the so-formedblanket onto an endless foraminous conveyor belt which passes through aheated chamber or housing. While in the chamber, the blanket is directedup 'an in cline'd plane and then passed back to thebel'tin such a manneras to break up the blanketand' thus redistribute the' staple fiberstherein. The

blanket of staple fibers is assisted up the inclined plane by means ofair pressure, that is, a series of nozzles arranged transversely of thedirection of travel of theblanket and directed substantially parallel tothe direction of travel and against the blanket to thus force the sameup the incline.

The belt is made of a foraminous material which is pervious to air.Directly under the belt and at a position coincident with thetermination of the inclined plane in an upward direction or slightlyback of such point with respect to the direction of travel of theblanket, a vacuum line or duct is arranged transversely of the belt andunderneath the same. The vacuum helps to break up the clumps of fibersin the blanket as it comes off the inclined plane and tends to turn theblanket back under the edge of the incline thus facilitating theredistribution of the fibers therein.

The chamber or housing through which the blanket passes maybe heated byany suitable means such as steam coils, electric lamps, and the like. Ifdesired,v hot air may be circulated through the chamber or housing tofacilitate the drying of the blanket passing therethrough, care beingtaken however that the force of the air or velocity thereof is such asnot to disturb or disrupt the blanket of staple fibers excessively whileon the conveyor belt. Any number of inclined planes may be positionedthroughout the chamber depending-of course, upon the amount ofredistribution that is required of the fibers in the blanket in order toinsure uniform and quick drying thereof.

In order tomore clearly understand the present invention, referenceshould be had to the accompanying drawing which depicts a preferredembodiment of the invention, it being understood, of course, that thisismerely intended in an illustrative sense and the invention is not to belimited thereby, but only insofar as the same may be limited by theappended claims.

In the drawing:

Figure 1 is the diagrammatic sectional side elevation view of apreferred form of apparatus,

Figure 2 is a plan view, partly in section, of the apparatus showninFigure l, and

Figure 3 is a plan view of an alternative em bodiment of the invention.

For the" purpose of simplicity of description ofthe invention, the samewill be described as it is applicable to'the' drylng' of a rayon stapleI to the drying of all types of fibers and in addition other materials,such as molding powders, and similar materials in granular form whichmay be dried in a manner in accordance with the present invention. Forexample, there may be mentioned wool, cotton, flax, hemp, regeneratedcellulose, cellulose ethers, cellulose esters, casein, alginates,resinous fibers, such as nylon, vinyl acetate, vinyl chloride, and otherresins which are well-known in the art.

Referring to the figures of the drawing, the apparatus of the presentinvention comprises a housing or chamber 3 having steam coils 4 arrangedin the top portionthereof. An endless conveyor belt 5 passes around therollers B and l and through the chamber 3. The belt 5 may be driven byany suitable means (not shown). As pointed out hereinabove, the belt 5is made of any material which is pervious to air and which will supporta blanket of staple fibers.

Positioned directly above the belt 5 intermediate the entrance and exitends of chamber 3 is a flat, rectangular, plate-like member 8 extendingtransversely of the belt and forming an incline therewith. The lower endof the plate-like member 8 rides snugly on the conveyor 5. Positionedabove the member 8 and transversely of the conveyor belt 5 is a plate orbafile-member 9, If desired, the members 8 and 9 may have a gentlycurved surface, i. e., convex or concave. V

Positioned in the lower part of the chamber 3 is a high-speed blower orfan 10 having a conduit I l attached to the exit port thereof Conduit Hextends upwardly alongside of the conveyor belt and is fastened orconnected to the transverse conduit !2 which is positioned above thebelt 5. Extending outwardly from conduit I2 is a series of small pipesor nozzles 13 which are directed against the inclined plate-like member8and nearly parallel to the conveyor belt 5.

To the intake port of the blower fan it there is attached a conduit I 4which is in turn connected to the upwardly extending conduit [5. Theconduit le'in turn is attached to the duct an open mouth across the topin very close proximity'therewith, said duct being positioned directlybelow the top edge of the inclined member 8. While in the embodimentshown the air is pulled through the duct I6, conduits l5'and l4 to theblower fan l0 and then out through conduits H and I2 and then out thenozzles or jets iii, the air may be drawn into the blower from theoutside the chamber 3, as shown in Figure 3. vacuum pump liic would haveto be attached to the duct 53. Drawing the air from outside the chamber3 would be satisfactory provided some means were employed for preheatingthe air in order not to lower the temperature inside the chamber 3 belowthe minimum required for efileient drying. The embodiment shown inFigures 1 and 2 of the drawing has the advantage of providing a closedtype air circulating system across the dryer and it is'not necessary topro- In such a case, however, a suitable attained.

blast of air and contains the blanket on the member 8. The blanket ridesover the edge of the member 8 and is pulled back under the edge of themember due to the force of the vacuum in the duct I6 under the belt 5.As the blanket passes over the edge of incline 8 and tumbles back ontothe belt, it is broken into separate pieces or chunks by the stream ofair passing the edge of member 8 induced by vacuum duct I6. The piecesor chunks fall back onto the conveyor belt in a disheveled andturned-over pattern thus redistributing the fibers in the blanket. Theblanket then proceeds out the chamber 3 through the exit port 19 and maythen be wound on rollers or deposited in cartons or other suitablecontainers as desired.

An important feature of the present invention is the use of vacuumimmediately below the top edge of the inclined member 8. It is importantthat this vacuum line be positioned di- 'rectly below the top edge orslightly back of such edge, in the direction of travel of the blanket inorder to insure the breaking up of the staple fiber blanket and theredistribution of the fibers therein. Without the-assistance of thevacuum, that is, merely allowing the blanket to pass up the inclinedplane and then drop back onto 7 the conveyor belt of its own weight, itfrequently happens that the blanket is merely flexed and it returns tothe conveyor belt with the fibers therein in approximately their samerelative position that they had prior to passing over the inclinedplane. Naturally, in such a case, proper redistribution of the fibers inthe blanket is not In many instances, however, flexing action alone maybe desirable. For example, in the case of a blanket of long lengthstaple fibers, i. e., 5 to 6 inches or more, it is extremely matty dueto such long fiber length. This matty condi tion makes it extremelydifiicult to completely break up the blanket and turn it over. Hence,the flexing action alone is valuable in such a case in that it disturbsthe matty condition thus exposing new surfaces and creates a more porousit which extends transverse of the belt 5 and has blanket. However, thebest results are obtained when using the vacuum in accordance with thepresent invention, since the fiber blanket is pulled back under the edgeof the member 8, because of the stream of air passing the edge of member8 induced by the vacuum, in such a manner as to break it up thusinsuring good redistribution of the fibers.

As previously pointed out, any type of heating means may be employed inthe dryer housing or chamber 3. The housing 3 may be of any desiredlength and size depending, of course, upon the material being dried andthe thickness of the layer or blanket which is passed therethrough. Anynumber of inclined members and associated apparatus may be employed atspaced intervals in the housing, depending, of course, upon the amountof redistribution of the fibers in the blanket or mat required ordesired. Any number of nozzles or jets I3 may be employed to assist theblanket up the inclined plane. The number of nozzles will depend uponthe weight of the blanket or thickness thereof andalso upon the angle ofinclination that the member 3 makes with the belt 5 and in thisconnection it should be noted that the angle of inclination may bevaried as desired or necessary. An angle of inclination of 5 to 20,'-ormore, has been found to be satisfactory.

The present invention provides a convenient means of redistribution,breaking up, or turn ing over of a staple fiber blanket as it passesthrough a dryer thus insuring quick and even or uniform drying of allthe fibers within the blanket. In addition, there are no moving partsinside the dryer and once the apparatus is set and properly adjusted, itwill operate indefinitely without any further regulation or closeobservance. The apparatus of the present invention is easily adapted touse with any of the known standard type of conveyor dryers and inaddition, the cost of installation and operation is small. Numerousother advantages of the present invention will be apparent to thoseskilled in the art.

It is to be understood that changes and variations may be made withoutdeparting from the spirit and scope of the invention as defined in theappended claims.

I claim:

1. An apparatus for drying a continuous blanket of staple fiberscomprising a drying chamber, foraminous conveying means in the chamberfor conveying the staple fiber blanket through the chamber, a memberhaving a smooth surface mounted in the chamber and extendingtransversely of the direction of travel of the blanket, said memberbeing inclined upwardly in the direction of travel of the blanket andpositioned in close proximity to the conveying means, means fordirecting the blanket up and over the member, and vacuum meanspositioned adjacent to and beneath the conveying means and having itsopen mouth in alignment with the elevated edge of the member forredistributing the fibers in the blanket as it returns to the conveyingmeans. i

2. An apparatus as defined in claim 1 in which the open mouth of thevacuum means is underneath the elevated edge of the inclined member.

3. An apparatus as defined in claim 1 wherein the conveying meanscomprises an endless conveyor belt pervious to air.

4. An apparatus asdefined in claim 1 wherein the means for directing theblanket up and over the member is pneumatic means.

5. An appartus for drying a continuous blanket of staple fiberscomprising a drying chamber, heating means in the chamber, endless beltconveyor means pervious to air for conveying a staple fiber blanketthrough the chamber, a plate in the chamber extending transversely ofthe direction of travel of the blanket, said plate being inclinedupwardly in the direction of travel of the blanket and having its fiberreceiving end contiguous to the conveyor belt, pneumatic means fordirecting the blanket up and over the plate, and vacuum means positionedadjacent to and beneath the conveyor belt for redistributing the fibersin the blanket as it returns to "the conveyor means, said vacuum meanscomprising a duct extending transversely of the direction of travel ofthe blanket and positioned beneath the conveyor means with its openmouth in alignment with the elevated edge of the plate.

6. An apparatus as defined in claim 5 wherein the pneumatic meanscomprises a conduit arranged transversely of the direction of travel ofthe blanket and positioned above the conveyor means, a series of nozzlesattached to and extending outwardly from the conduit and directed towardthe plate, and means for supplying air to the conduit.

7. An apparatus as defined in claim 6 wherein there is a second fiatplate positioned above the first plate to confine the blanket on thefirst plate.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 473,263 Proctor Apr. 19, 1892 847,038 Ayres Mar. 12, 19071,169,682 Sargent Jan. 25, 1916 1,778,318 Haas Oct. 14, 1930 2,360,257Muller et a1. Oct. 10, 1944 FOREIGN PATENTS Number Country Date 50,883Austria Nov. 29, 1911 238,094 Switzerland June 30, 1945

